1. Field of the Invention
The present invention relates to a menu selection device in a microwave oven, and more particularly, to a menu selection device in a microwave oven constructed such that a single display device can be used in a state where it is divided into a menu guide unit and a menu selection unit.
2. Description of the Prior Art
Generally, a touch screen is a special cathode ray tube screen with an infrared film, and more specifically, a device for sensing a position touched by a user on the cathode ray tube screen and outputting information corresponding to the sensed position. The touch screen is widely used as a device for selecting and inputting various signals in automated teller machines for banks, information kiosks in public places and a variety of electronic appliances.
Recently, as a great deal of various high quality electronic products have been produced, the touch screen has been largely used in the electronic appliances. Even in case of a microwave oven, the touch screen is also used as a device for displaying and selecting menus.
FIG. 1 is a perspective view of a conventional microwave oven with a touch screen installed therein, and FIG. 2 is a view showing a use state where menus are displayed on the touch screen.
That is, in the conventional microwave oven, a control panel 7 is installed at a side of a cooking chamber 5, i.e. a front portion of an electronic equipment installation chamber in which a magnetron and various kinds of electronic parts are installed. Various kinds of buttons, a display device 1 for displaying and inputting menus, and the like are installed at the control panel 7.
As shown in FIG. 2, the display device 1 is composed of the touch screen on which various kinds of menus provided in the microwave oven are displayed so that a user can personally select a desired menu among the displayed menus. Further, the display device 1 installed at the control panel 7 of the conventional microwave oven is constructed such that both display and input of the menus can be performed on the entire area thereof. Therefore, the display device 1 provided in the conventional microwave oven should be constructed such that the entire area thereof is manufactured in the form of the touch screen.
To this end, the microwave oven should also be constructed to have a control configuration shown in FIG. 3.
FIG. 3 shows the configuration in which the display device I for use in the conventional microwave oven is composed of an infrared touch screen for sensing whether the touch screen has been touched. The infrared touch screen comprises a processor 10 for generating a relevant control signal by accessing software through an input means such as a finger or a special pen and for processing a coordinate of a position on a CRT display unit 18 touched by the input means, an infrared rays generating unit 14 for generating infrared rays in response to the control signal generated from the processor 10, an infrared rays receiving unit 16 for determining the presence of the infrared rays generated from the infrared rays generating unit 14, and the CRT display unit 18 for displaying the coordinate of the predetermined position touched by the input means on the basis of the presence of the infrared rays. In addition, reference numerals 12a and 12b designate write and read buffers. The write buffer 12a temporarily stores the control signal received from the processor 10 and then transmits the stored signals to the infrared rays generating unit 14, whereas the read buffer 12b also temporarily stores data related to the infrared rays from the infrared generating unit 14 and transmits the stored data to the processor 10.
In addition, the infrared rays generating unit 14 is constructed to transmit the infrared rays along an x-axis (abscissa of the figure) and y-axis (ordinate of the figure) of the CRT display unit 18. Light-emitting devices provided along the x- and y-axes of the infrared rays generating unit 14 are provided to correspond to light-receiving devices of the infrared rays receiving unit 16 to be described later in detail. In FIG. 3, it is shown that the fifteen (15) light emitting/light receiving devices are placed along the x-axis, and eleven (11) light-emitting/light-receiving devices are placed along the y-axis of the CRT display unit.
The infrared rays receiving unit 16 performs a function of determining the presence of the infrared rays transmitted from the infrared rays generating unit 14 so that the processor 10 can sense an touch action exerted on the CRT display unit 18. According to the number of the light-emitting/light-receiving devices, resolution of the touch screen is determined. If the aforementioned light-emitting/light-receiving devices are provided, the resolution becomes “15×11”.
A coordinate determination process in the CRT display unit 18 of the conventional infrared rays touch screen constructed as such will be described as follows.
First, if the processor 10 supplies a predetermined control signal to the infrared rays generating unit 14 through the write buffer 12a, the infrared rays generating unit 14 generates the infrared rays in response to the control signal from the processor 10 and transmits the generated infrared rays onto the infrared rays receiving unit 16 in the directions of the x- and y-axes. When the touch action is exerted on a specific position of the CRT display unit 18 together with the transmission of the infrared rays, any one piece of the data corresponding to the transmitted infrared rays is not transmitted to (i.e. received at) the infrared rays receiving unit 16. Based on pieces of the data received in the infrared rays receiving unit 16, accordingly, the processor 10 determines that the touch action has been made at the predetermined position of the CRT display unit 18.
In other words, if all the infrared rays transmitted from the infrared rays generating unit 14 arrive at the infrared rays receiving unit 16, it indicates that any input devices have not come into contact with the CRT display unit 18. However, if any infrared rays do not arrive at specific light-receiving devices of the infrared rays receiving unit 16, it indicates that the input device is in contact with the CRT display unit 18, i.e. a specific position of the touch screen.
For example, the processor 10 assigns the data value “1” to the respective fifteen light-emitting devices of the infrared rays generating unit 14 placed along the x-axis of the CRT display unit and then causes the infrared rays having the assigned value to be transmitted to the corresponding light-receiving devices of the infrared rays receiving unit 16 placed along the x-axis thereof. The infrared rays receiving unit 16 receives the transmitted infrared rays having the assigned data value, i.e. value of “1”, and the processor 10 reads the value of “1” and determines that any input devices have not come into contact with the CRT display unit.
However, if the specific light-receiving devices of the infrared rays receiving unit 16 do not receive the infrared rays transmitted from the corresponding light-emitting devices of the infrared rays generating unit 14, the processor 10 reads a data value “0” instead of the assigned data value “1”. In such a case, the processor 10 determines that the input device is in contact with the CRT display unit 18 on the predetermined position thereof, as described above.
Further, the processor 10 assigns the data value “1” to the eleven light-emitting devices of the infrared rays generating unit 14 placed along the y-axis and then causes the infrared rays having the assigned data value “1” to be transmitted to the corresponding light-receiving devices of the infrared rays receiving unit 16 placed along the y-axis, the processor reads the data value of the infrared rays transmitted to the infrared rays receiving unit 16 and determines a state where the input device has come into contact with the CRT display unit. Through such a process, the x and y coordinates of the predetermined position on the touch screen, which is touched by the input device, can be obtained.
In order to sense whether any positions on the CRT display unit 18 have been touched by the input means as above, the entire area of the CRT display unit 18 must be constructed in the form of the touch screen so that the configuration and sensing method shown in FIG. 3 can be established and performed. Therefore, according to the conventional microwave oven, the entire area of the display device 1 must be processed in the form of the touch screen in order to sense the touch action throughout the entire area of the display device 1.
In addition, if cooking menus are displayed on the display unit 1 constructed in the form of the touch screen as shown in FIG. 2, selection of a desired cooking menu can be made by merely bringing the input device into contact with the position on the display unit where the desired cooking menu is displayed. As an example, if the user intends to select a “POPCORN” menu, he/she selects the “POPCORN” menu by simply bringing the input device into contact with a fourth line (item) on which “POPCORN” is displayed.
As described above, according to the conventional microwave oven, the display and selection of the cooking menus are performed by using the display device 1 of which entire area is constructed in the form of the touch screen.
However, the conventional microwave oven in which the entire area of the display device 1 thereof is constructed and used in the form of the touch screen has the following problem.
In products employing the touch screen, the size of the touch screen should be determined by considering a space needed for installation of the touch screen, a condition for provision of various menus in the products, and increase of production costs due to the usable size of the touch screen. It is because the space needed for the installation of the touch screen should be determined in proportion to the size of the relevant product and the amount of the menus of the product displayed on the touch screen should also be determined according to the size of the touch screen.
As an example, as shown in FIG. 1, the microwave oven is constructed such that the space in which the display device 1, such as the touch screen, for use in the menu display and selection can be installed is restricted to the one side of the cooking chamber 5. Thus, in order to properly display the various menus of the product onto the display device 1 within the restricted space, specific arrangement corresponding thereto is further needed.
It is preferred that the whole display device 1 installed at the possible maximum size be constructed in the form of the touch screen in the conventional manner. However, the costs required for constructing the entire area of the display device in the form of the touch screen cause the increase of the production costs of the product. Accordingly, there is a problem in that it deteriorates merchantability of the product.